The removal of water and other contaminants, such as oxygenates and/or sulfur compounds, from light hydrocarbons is often performed to produce a clean hydrocarbon product. The clean hydrocarbon product can be further treated using catalytic reactions, such as catalytic isomerization, to produce other hydrocarbons, increase octane, improve the product value, and/or the like. In particular, catalysts that are typically used for catalytic isomerization and other catalytic reactions are very sensitive to water, oxygenates, and sulfur compounds, which can cause deactivation of the catalyst, thereby reducing catalyst life, increasing the number of catalyst regenerations, and/or requiring complete replacement of the catalyst.
One conventional process for removing water and other contaminants from light hydrocarbons employs a bed arrangement that contains a relatively large pore molecular sieve as an absorbent material. A light hydrocarbon stream is passed through the bed arrangement and the molecular sieve absorbs much of the water and other contaminants from the stream to produce a clean hydrocarbon product. As the molecular sieve removes the undesirable components from the stream, its surface and pores become saturated with water and to a lesser extent the other contaminants, causing the molecular sieve to become less active. To restore its activity, the molecular sieve is regenerated at higher temperatures to help remove the absorbed water and other contaminants. Although water is readily removed from the molecular sieve during regeneration, the other contaminants tend to remain and react at the higher temperatures to form a gummy residue. The gummy residue steadily builds up during each additional regeneration, plugging the pores and causing premature permanent deactivation of the molecular sieve. Since regeneration at this point is no longer effective to restore activity, the molecular sieve needs to be replaced, which is expensive and time consuming.
Accordingly, it is desirable to provide methods and apparatuses for treating a hydrocarbon-containing feed stream using an absorbent material(s) to remove water and other contaminants to produce a clean hydrocarbon product without causing premature permanent deactivation of the absorbent material(s). Moreover, it is desirable to provide methods and apparatuses for treating a hydrocarbon-containing feed stream to produce a clean hydrocarbon product using an absorbent material(s) that may be frequently regenerated to restore activity without causing a steady buildup of gummy residue on the absorbent material(s). Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background.